new information marker
Definition - A spoken form — e.g. a word, a particle, or an inflection— that the speaker uses either consciously or unconsciously to convey the idea that what he or she is saying is new information.

Example Usages -

1. "For example, Tomlin 1995 argues that Japanese wa is not a topic marker, but a ‘new information’ marker. Tomlin’s arguments are based primarily on experimental evidence and the observation that wa is typically used to mark noun phrases referring to entities that are ‘new’ in the sense that they are not currently salient in the discourse."
(Source: Topic, Focus, and the Grammar-Pragmatics Interface, Jeanette K. Gundel )

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